Public announcement system



FIG. 1 is a perspective view of a public announcement system showing our new design;

FIG. 2 is a front elevational view thereof, the rear elevational view being a mirror image thereof;

FIG. 3 is a side elevational view thereof, the opposite side elevational view being a mirror image thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof.

The broken lines shown are included for the purpose of illustrating portions of the public announcement system that form no part of the claimed design. 

CLAIM The ornamental design for a public announcement system, as shown and described. 